首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2495篇
  免费   144篇
  国内免费   6篇
耳鼻咽喉   9篇
儿科学   72篇
妇产科学   24篇
基础医学   380篇
口腔科学   89篇
临床医学   332篇
内科学   519篇
皮肤病学   70篇
神经病学   293篇
特种医学   81篇
外科学   301篇
综合类   6篇
一般理论   3篇
预防医学   216篇
眼科学   25篇
药学   121篇
中国医学   1篇
肿瘤学   103篇
  2023年   18篇
  2022年   24篇
  2021年   45篇
  2020年   35篇
  2019年   41篇
  2018年   33篇
  2017年   46篇
  2016年   74篇
  2015年   49篇
  2014年   74篇
  2013年   165篇
  2012年   172篇
  2011年   165篇
  2010年   110篇
  2009年   129篇
  2008年   169篇
  2007年   166篇
  2006年   155篇
  2005年   181篇
  2004年   152篇
  2003年   141篇
  2002年   132篇
  2001年   26篇
  2000年   14篇
  1999年   30篇
  1998年   27篇
  1997年   21篇
  1996年   19篇
  1995年   24篇
  1994年   15篇
  1993年   10篇
  1992年   20篇
  1991年   8篇
  1990年   7篇
  1988年   10篇
  1987年   8篇
  1986年   7篇
  1985年   10篇
  1984年   6篇
  1983年   8篇
  1982年   8篇
  1981年   9篇
  1979年   6篇
  1978年   12篇
  1977年   5篇
  1976年   4篇
  1975年   4篇
  1972年   4篇
  1970年   6篇
  1966年   6篇
排序方式: 共有2645条查询结果,搜索用时 15 毫秒
101.
102.
Journal of Thrombosis and Thrombolysis - The aim of the study was to compare nationwide time trends of prescribed oral anticoagulants (OAC) with the time trend of genitourinary bleedings (GUB) in...  相似文献   
103.
Microglia most likely appeared early in evolution as they are not only present in vertebrates, but are also found in nervous systems of various nonvertebrate organisms. Mammalian microglia are derived from a specific embryonic, self‐renewable myeloid cell population that is throughout lifetime not replaced by peripheral myeloid cells. These phylogenic and ontogenic features suggest that microglia serve vital functions. Yet, microglia often are described as neurotoxic cells, that actively kill (healthy) neurons. Since it is from an evolutionary point of view difficult to understand why an important and vulnerable organ like the brain should host numerous potential killers, we here review the concept of microglia neurotoxicity. On one hand it is discussed that most of our understanding about how microglia kill neurons is based on in vitro experiments or correlative staining studies that suffer from the difficulty to discriminate microglia and peripheral myeloid cells in the diseased brain. On the other hand it is described that a more functional approach by mutating, inactivating or deleting microglia is seldom associated with a beneficial outcome in an acute injury situation, suggesting that microglia are normally important protective elements in the brain. This might change in chronic disease or the aged brain, where; however, it remains to be established whether microglia simply lose their protective capacities or whether microglia become truly neurotoxic cells. GLIA 2014;62:841–854  相似文献   
104.
Objectives: Depression in dementia is common, but the prevalence rates differ according to the populations studied and which diagnostic tools are being used. The aim of this study is to explore the prevalence of depression among patients referred to a memory clinic or an outpatient clinic as measured by the Cornell Scale of Depression in dementia (CSDD) and to investigate which factors are associated with depression.

Method: The CSDD was completed for 1470 patients on their first visit to a memory clinic or an outpatient clinic. The prevalence of depression using three different cut-off points was calculated. Logistic regression and correlation analyses were performed.

Results: Half of the patients had dementia. The mean CSDD was 6.7 (SD: 5.3) for the whole group, and 50.2% had a score above 5, whereas 37.5% had depression defined as a CSDD score above 7, and 14.1% had a score above 12. The mean scores were higher among those with dementia other than Alzheimer's disease, those with previous depression, and those with greater impairment in the activities of daily living (ADL). In the logistic regression analyses, younger age, ADL dysfunction, and previous depression were significantly associated with higher CSDD scores.

Conclusion: We found that depressive symptoms are common among patients referred for a dementia assessment in specialist health care. The strongest factors associated with depressive symptoms were younger age, ADL impairment, and previous depression.  相似文献   

105.
106.
Initiation of adaptive immunity to particulate antigens in lymph nodes largely depends on their presentation by migratory dendritic cells (DCs). DC subsets differ in their capacity to induce specific types of immunity, allowing subset-specific DC-targeting to influence vaccination and therapy outcomes. Faithful drug design, however, requires exact understanding of subset-specific versus global activation mechanisms. cDC1, the subset of DCs that excel in supporting immunity toward viruses, intracellular bacteria, and tumors, express uniquely high levels of the pattern recognition receptor TLR3. Using various murine genetic models, we show here that both, the cDC1 and cDC2 subsets of cDCs are activated and migrate equally well in response to TLR3 stimulation in a cell extrinsic and TNF-α dependent manner, but that cDC1 show a unique requirement for type I interferon signaling. Our findings reveal common and differing pathways regulating DC subset migration, offering important insights for the design of DC-based vaccination and therapy approaches.  相似文献   
107.
108.
During Alzheimer’s disease (AD) progression, microglial cells play complex roles and have potentially detrimental as well as beneficial effects. The use of appropriate model systems is essential for characterizing and understanding the roles of microglia in AD pathology. Here, we used organotypic hippocampal slice cultures (OHSCs) to investigate the impact of microglia on amyloid beta (Aβ)‐mediated toxicity. Neurons in OHSCs containing microglia were not vulnerable to cell death after 7 days of repeated treatment with Aβ1‐42 oligomer‐enriched preparations. However, when clodronate was used to remove microglia, treatment with Aβ1‐42 resulted in significant neuronal death. Further investigations indicated signs of endoplasmic reticulum stress and caspase activation after Aβ1‐42 challenge only when microglia were absent. Interestingly, microglia provided protection without displaying any classic signs of activation, such as an amoeboid morphology or the release of pro‐inflammatory mediators (e.g., IL‐6, TNF‐α, NO). Furthermore, depleting microglia or inhibiting microglial uptake mechanisms resulted in significant more Aβ deposition compared to that observed in OHSCs containing functional microglia, suggesting that microglia efficiently cleared Aβ. Because inhibiting microglial uptake increased neuronal cell death, the ability of microglia to engulf Aβ is thought to contribute to its protective properties. Our study argues for a beneficial role of functional ramified microglia whereby they act against the accumulation of neurotoxic forms of Aβ and support neuronal resilience in an in situ model of AD pathology.  相似文献   
109.
110.
Phosphorylation events on proteins during growth and stress/starvation can represent crucial regulation processes inside the bacterial cell. Therefore, serine, threonine and tyrosine phosphorylation patterns were analyzed by two powerful complementary proteomic methods for the human pathogen Staphylococcus aureus. Using 2D-gel analysis with a phosphosensitive stain (Pro-Q Diamond) and gel-free titanium dioxide based phosphopeptide enrichment, 103 putative phosphorylated proteins with successfully mapped 68 different phosphorylation sites were found in the soluble proteome of S. aureus. Additionally, in a proof of concept study, 8 proteins phosphorylated on arginine residues have been identified. Most important for functional analyses of S. aureus, proteins related to pathogenicity and virulence were found to be phosphorylated: the virulence regulator SarA, the potential antimicrobial target FbaA and the elastin-binding protein EbpS. Besides newly identified phosphorylation sites we compared our dataset with existing data from literature and subsequent experiments revealed additional phosphorylation events on highly conserved localizations in FbaA. Differential analysis of phosphorylation signals on the 2D-gels showed significant changes in phosphorylation under different physiological conditions for 10 proteins. Among these, we were able to detect newly appearing signals for phosphorylated isoforms of FdaB and HchA under nitrosative stress conditions.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号